<!DOCTYPE html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
	<style>
		col.selected || td {
			background: gray;
			color: white;
			font-weight: bold;
		}
	</style>
</head>

<body>
	<table border="1">
		<colgroup>
			<col span="2" />
			<col class="selected" />
		</colgroup>
		<tbody>
			<tr>
				<td>A
				<td>B
				<td>C
			</tr>
			<tr>
				<td colspan="2">D</td>
				<td>E</td>
			</tr>
			<tr>
				<td>F</td>
				<td colspan="2">G</td>
			</tr>
		</tbody>
	</table>
</body>

</html>